The MPs' report also raises serious question marks over transport plans for the anticipated 12 million visitors to the site at Greenwich, south-east London, in 2000.

But it says the Government was right to press ahead with the controversial project and predicts that the Dome will be "breathtaking" when completed.

The Labour-dominated Commons Culture, Media and Sport Committee, says more information is needed on what would go inside the Dome.

"A journey into the unknown"

It calls for the "Dome Secretary", Peter Mandelson, to spend longer at the Dispatch Box in the House of Commons taking questions on the subject from MPs.

The Minister Without Portfolio currently faces just five minutes of questioning a month.

The report says: "At times the process of discovering the proposals for the content of the Dome was akin to drawing teeth.

"From what we know so far, the Millennium Experience is not so much a journey through time, as a journey into the unknown.

"We know more about what the Experience will not be than what it will be."

The MPs warn that, from the little they did know about plans for inside the Dome, they had not been inspired to "share the excitement of the organisers, much as we would like to".

Transport plans criticised

The committee, chaired by Labour MP Gerald Kaufman, says more information is vital to generate public support and excitement for a project funded with public money.

The committee is also concerned about the lack of firm details on sponsors for the project, given the tight deadline, and the absence of a contingency plan if the project ran short of funds.

It also calls for a firm decision on whether the Millennium Experience would end on December 31, 2000, or continue for another year.

However, the committee's biggest criticisms are reserved for transport arrangements to the site.

MPs say they are "deeply concerned" by London Underground's attitude and call for the development of signalling systems allowing 24 trains an hour to arrive at the site to be made "an utmost priority".

They also recommend development of park-and-ride sites linked to the Underground network and for ticket packages to include Tube fares with admission tickets to the Experience.

"Breathtaking in execution"

But despite the criticism the Dome has attracted, the MPs said they were enormously impressed by it on a site visit.

The report says: "As we discovered, the structure has great power, even in skeletal form, to excite and inspire.

"The Dome is magnificent in conception and likely to be breathtaking in execution."

Mr Mandelson said he was "extremely encouraged" by the report.

He said: "I think their concerns are misplaced in relation to transport, accountability and marketing, but with a project of this magnitude there is no room for complacency."